As I have traveled the county this past week, I have seen countless numbers of fruit trees already in green-tip stage, pink-tip stage, or already in bloom. This is a cause for concern as it is only the end of February, and the threat of frost or freeze is far from over. For Sampson County, the last average frost date is April 1st, plus or minus 12 days. This means that these early blooms have to make it almost 50 more days without frost or freeze to produce fruit, which is highly unlikely.
In the event of a possible frost or freeze, the National Weather Service (NWS) will issue warnings according to the forecasted weather conditions in our area. The wording of these warnings tells the grower or homeowner how they can react. If winds below 10 mph and minimum temperatures above or equal to 32°F are forecasted, a frost warning will be issued. If winds below 10 mph and minimum temperatures below 32°F are forecasted, a frost/freeze warning will be issued. When winds above 10 mph and minimum temperatures below 32°F are forecasted, a freeze warning will be issued. Thus, the frost and frost/freeze warnings imply that the grower can likely provide successful protection, while a freeze warning means the winds will be too high to allow successful use of irrigation protection. Irrigation is typically used by commercial growers to protect their crops, but what options are available to small growers or homeowners?
For a frost warning a small grower or homeowner can use burlap or bed sheets placed over their trees for frost protection. For a frost/freeze or a freeze warning the best method for protection is to cover the trees completely with row covers or plastic that completely envelops the tree and extends all the way to the ground. A 100-watt incandescent light bulb placed under the cover, hanging from a branch will give additional protection from cold injury. It is important to remove the coverings during the day to avoid sunscald to the trees and re-cover when advisories are forecast. For new fruit tree plantings, North Carolina State University (NCSU) recommends planting trees with a minimum of 750 chilling hours. Chilling hours is the time that a tree remains in dormancy before blooming in spring. Fruit trees with 750 chilling hours will usually begin to bloom at or near April 1, which is the average last frost date for our area. Trees with higher chilling hours will bloom later than April 1 and should not be affected by average or late frost events.
For more information on fruit trees and frost protection visit the NCSU fruit tree resource catalog at https://content.ces.ncsu.edu/producing-tree-fruit-for-home-use.
Don’t forget that the Sampson County Extension Service is offering the Sampson County Friends of Horticulture program this year. This program offers monthly “How To” horticultural seminars targeting homeowners and gardeners of Sampson County. If you’d like to learn how to have a better lawn in 2017, pre-register for our next seminar. Our 2017 calendar is as follows:
March 23 – Best Management Practices for Turfgrass and Lawns
April 20 – Managing the Red Imported Fire Ant
May 18 – Soils – How to Soil Sample and Understand a Soil Report
June 15 – The Buzz about Bees
July 20 – Growing and Maintaining Pecans
August 17 – Raised Bed Gardening
September 21 – Calibrating a Hand Sprayer and Spreader
October 26 – Ridding your yard of Moles and Voles
Classes begin at 6 p.m. at the Sampson County Extension Center Livestock Facility, 93 Agriculture Place, Clinton. Registration is $5 per class. You select and pay only for the classes you choose to attend. To sign up for classes you must pre-register. You can register by calling the Sampson Extension office at (910) 592-7161, or by signing up online at http://go.ncsu.edu/sampsonhort. Online registration will open one month before the class is scheduled to begin.
Brad Hardison is an agricultural extension agent specializing in horticulture.